Control device for pneumatic-dispatch-tube apparatus



July 30, 1929. s. OLSON CONTROL DEVICE FOR PNEUMATIC DISPATCH TUBE APPARATUS Filed Sept. 10, 1927 2 Sheets-Sheet l Il 7 8i .3 a; as 7 36 I X/ a 2/5 22 @VEJ Z OJ". I

%fz e5s July 30, 1929. s. OLSON 1,722,536

CONTROL DEVICE FOR PNEUMATIC DISPATCH TUBE APPARATUS Filed Sept. 10, 1927, 2 Sheets-Sheet 2 @VE ZOZ. ifzjess. 61 Z5191 5 OZ) Patented July 30, 1929.

U N l T ED ill SAMUEL OLSON, OF OAK PARK, ILLINOIS,

ASSIGNOR TO SAMUEL OLSON & COMPANY,

OF CHICAGO, ILLINOIS, A CORPORATION OF ILI IINOIS.

CONTROL DEVICE FOR PNEUMATIO-DISPATCH-TUBE APPARATUS.

Application filed September This invention relates to improvements in pneumatic dispatch tube apparatus, and more particularly to controlling devices for reguating the flow of air through the system. This control device is especially adapted for use in systems in which a minimum flow of. air is permitted through the tubes when no carriers are in transit, while automatically increasing the flow of air through the tubes instantaneously upon the insertion of a carrier in the tube, and again automatically reducing the flow of air in the tubes upon the discharge of the last carrier therefrom.

The object of the present invention is to provide an improved controlling device simple in construction and positive in operation, in which the valve opens rapidly to permit full suction in the tubes to impel a carriei from station to station, and when the carrier is ejected from the tube the valve then closes in a smooth and easy manner. It consists of certain features and elements of construction in, combination, as herein shown, and described and as indicated by the claims.

In the drawings:

Figure 1 is a somewhat diagrammatic V16 of a complete circuit of a pneumatic dispatch tube apparatus showing my improved controlling device arranged in proper relation in the system.

Figure 2 is a vertical section through the controlling device taken at a medial plane through the transmission tubes.

Figure 3 is a view similar to Figure 2, il-

' lustrating a modified construction.

The pneumatic dispatch systems in which this improved control device is designed to,

operate, is of the general suction or vacuum type, and as illustrated diagrammatically in Figure 1 comprises a suction drum, 1, con nected by a supply pipe, 2, to the housing, 3, of a globe valve. It will be understood that the suction drum, 1, may be maintained under reduced pressure by any suitable means, such as a suction pump (not shown). The valve housing, 3, is connected to an auxiliary housing, 4, by a pipe coupling, 5, said auxiliary housing also having a connection by a pipe, 6, to the line proper. The latter comprises two transmission tubes, 7 and 8, which constitutes outgoing and return runs for the pair of stations which they serve. At the station adjacent the control mechanism the outgoing tube, 7, is provided with a usual bell shaped mouth, 9, for insertion of a carrier t 10, 1927. Serial No. 218,777.

be transmitted, while the end of the same tube at the remote station is provided with a spring discharge flap, 10, formed in a coupling, 11, engaging the ends of both tubes. The end of return run tube, 8, at the remote station is provided with a spring flap, 12, also connected to coupling, 11, through which a carrier is inserted for transit to the station at the control end of the" system, and for distinuously or for any great length of time; .therefore it is unnecessary to have the line subject to full suction except when a carrier is in the tubes for transmission; and to facilitate immediate transmission of the carrier upon its insertion in the tube a restricted flow of air or partial vacuum is maintained through the tubes when the valve is closed. This restricted flow of air is had by means of an aperture, 16, formed in the partition wall of the valve housing adjacent said valve, permitting communication of the tubes with the source of suction independently of the valve at all times.

The valve, 15, is controlled by a pneumatic comprising a'fiexible diaphragm, 17, having one side thereof subject to the suction in line, 2, through an opening, 18, formed concentric with the chamber, 19. A valve stem, 20, ex? tends through the opening, 18, and is rigidly connected at its ends to the diaphragm, 17 and valve, 15, for a direct connection. When the valve is closed the line is under partial Vacuum, which is communicated from chamber, 19, to chamber, 21, by a bypass, 22, connecting the ports, 23, and 24, in the respective chambers. This by pass, 22, is controlled by an adjustable needle valve, 25. The chamber, 21, is vented at atmospheric pressure when a carrier is introduced in the tube the insertion of the carrier reduces the flow of air in the line and increases the vacuum, and since the will be forced inwardly in chamber, 19, im parting corresponding movement to the valve stem, 20, which opens valve, 15, to admit full suction in the line, thereby applying full im- Chamber, 31, is provided with ports, 33, so

that it may at all times be subject to atmospheric pressure; while chamber, 32, is arranged to have direct communication with the pressure in the line. A rod, 3 1, extends transversely through both chambers and is rigidly secured adjacent one end to the diaphragm, 30, while the other end is slid-ably supported in the housing, a. Like the first penumatic, the diaphragm, 30, will be actuated in response to increased vacuum in the line resulting from inserting a carrier in the tube. The pressure in chamber, 31, being considerably greater than in chamber, 32, will cause the diaphragm to be forced into chamber The rod, 34, may be arranged to vent chamber, 21, of the first pneumatic at atmospheric pressure in any suitable manner herein shown, to include a valve, 35, on the end of said rod, adapted to vent an auxiliary chamber, 26, internally connected with the chamber, 21. This action takes place when the diaphragm is actuated by a reduced pressure in the line as above described. When the diaphragm, 30, responds to a reduced pressure in the line, it compresses a spring, '36, disposed about the rod, 341, which tends to return the diaphragm, 30, to normal position,

and this takes place when the line is vented to atmosphere after the last carrier is ejected from the transmission'tube.

Although the diaphragm, 30, would be restored to normal position by venting of the line after the carrier is ejected from the tube andwould thus start the closing of valve, 15, it is preferable to insure closure of this valve as soon as possible after the carrier has left the tube. For this purpose the partition of the housing, 1, is arranged in the direct path of flow of air through the ,pipe, 6; this partition providinga port, 37, extending longitudinally of said pipe in approximately cen- 'tral position relative thereto and concentric with rod, 3 1-. A baffle, 38, is mounted on said rod and movable therewith by movement imparted by the diaphragm, 30. The-baffle is larger than the port, 37, having its outer periphery extending beyond the outlines of said port and normal ly spaced at a distance there- "from. As" may be seen, the battle is movable towardthe port Whenthe diaphragm, 30, is

responding to an increased vacuum in the line; although it never closes the port, it is adapted to receive the full force of the gust of air that follows after the carrier has been discharged from the tube, and this moves the battle with. the rod and diaphragm, 30, to nor mal position with the assistance of the compressed spring, 36, thereby closing the vent in the auxiliary chamber, 26. Immediately upon closing of the valve, 35, the suction in the line begins to reduce the pressure in chamber, 21, of the first pneumatic through the connected ports, 23 and 24;, until the pressure inthe chambers, 19 and 21, issubstantially the same, thereby balancing the diaphragm, 17,

which in turn permits valve, 15, to close. The speed at which the valve, 15, closes is c0ntrolled by the adjustment of the needle valve, 25, which determines the rate of flow of air from chamber, 21, to chamber, 19. When the valve, 15, is opened it compresses a spring, 39, which assists in securing prompt seating of the valve, 15. It will be noted that the needle valve may be adjusted so that the pressures in chambers, 19 and 21, will equalize slowly, thereby providing a cushioning effect for the valve, 15, as it closes. After the valve is closed a restricted flow of air or partial vacuum is again setup through port, 16, so that the system shall be ready to repeat the cycle.

A modified construction for controlling the valve, 15, is illustrated in Figure 3, showing the valve in open position, while the second pneumatic, 4:5, is shown immediately after the sudden rush of air, (resulting from the delivery of a carrier from the tube) has entered the housing, l, causing the pneumatic to commence functioning to close the valve. The lower portion of the mechanism including the first pneumatic and the valve proper are exactly the same as heretofore described, The second pneumatic serves the same purpose in this construction as in that described, thatis, controlling the valve, 15, through the first pneumatic. ihis pneumatic of the modified construction includes a flexible diaphragm, 15, having chambers, -16 and 17,0n opposite sides thereof; chamber, 46, is provided with vent openings, 13, to subject said chamber to atmospheric pressure, While chamber, 47, normally communicates with the line through a concentric opening, 19. These chambers are provided with ports, and 51, connected by a by-pass, 52, which controlled by an adjui-itablc needle valve, so that the pressures in the chambers may be balanced or equalized. The opening, 49, is controlled by a valve, 54, formed on the on d of the sleeve, 55, which is slidably mounted on a rod, 56. Said rod extends through the chambers and into the housing, 1, and is rigidly connected to the diaphragm, 45, and movable therewith. The valve, 54, is normally held in open position-by aspring, 57 mounted about'the sleeve, inter mediate a spider member, 58, disposed around the valve, and a baflie, 59, connected to'the opposite end of the sleeve. The spring, 57 is suitably .tensioned from the outside of the 1'1'iec11anisn'i,by means of a pair of rods, 60, extending parallel to and on opposite sides of the sleeve with their ends fixed to said spider, and extending through the baffle, 59,v thence through the housing, 4, with their outer ends secured to a cross bar, 61. Said cross bar carries an ad usting screw, 62, engaging the housing, 4, and a locking nut, 63, on the screw.

1 he inner partitions in the housing, 4, extend into the path of air flow, arranged to form a port, 64, extending parallel to the path of air flow in approximately central alignment with pipe, 6. The baifle, 59, which isconsiderably smaller than said port, is disposed therein and is adapted to permit air flow through the line at all times. The end of rod, 56, beyond the baffle, is provided with a collar, 65, for limiting the movement of the battle and sleeve, 55, due to the spring, 57. A coil spring, 66, is disposed intermediate said collar and the wall of housing, 4, and is compressed when diaphragm, 45, is actuated to move stem, 56. The opposite end of rod, 56, adjacent the wall of chamber, 46, serves as a slide valve, 67, adapted to vent the auxiliary chamber, 26, of the first pneumatic, at atmospheric pressure, when said rod is actuated by diaphragm, 45, by increased vacuum in the line.

- It will now be clear that the valve, 15, is normally closed and valve, 54, is normally open, while a restricted flow of air or partial vacuum is permitted through the system by the opening, 16, adjacent valve, 15. When a carrier is inserted in the tube, the vacuum in the line is increased, thereby reducing the pressure in chamber, 47, faster than it can be equalized by chamber, 46, through the needle valve, 53, which unequal pressure is responded to by the diaphragm, 45, moving into chamber, 47, and accordingly moving the rod, 56, against the reaction of spring, 66,thus instantaneously venting chamber, 21, (of the first pneumatic) to atmospheric pressure through the auxiliary chamber, 26, and slide valve, 67. The chamber, 19, is also under the pressure in the line, which upon the venting of chamber, 21, will actuate diaphragm, 17, and open the valve, 15, through the stem, 20. These operations, though dependent upon each other, permit positive and quick valve action to give full suction to the carrier in the tube. The sudden rush of air following the delivery of the carrier from the tube, impinges against baffie, 59, and forces it with the sleeve along the rod, 56, against the react-ion of spring, 57, to close the opening, 49, in chamber, 47, by the valve, 54. The chambers, 46 and 47 will be practically balanced in pressure by way of the needle valve, 53, thereby permitting the diaphragm, 45, to return to normal position and causing the rod, 56, by its valve,

67, to close the vent in the auxiliary chamber, 26. The chambers, 19 and 21, will then become equalizedto the pressure in the line through needle valve, 25, thereby restoring diaphragm, 17, to its normal position and closing valve, 15, so that the system is again ready to repeat the cycle.

I claim:

1. In a pneumatic dispatch apparatus including a transmission tube for a carrier with an air line connecting it to a source of suction, a normally closed valve interposed in the line between the tube and the source of suc tion, a reduced flow of air being permitted through the tube when the valve is closed, a pneumatic provided with a diaphragm forming two chambers, both being subjected to suction when the'valve is closed, said diaphragm being directly connected to said valve for controlling the same; a second penumatic provided with a diaphragm, a chamber on one side thereof being subjected to the pressure inside the tube, the chamber formed on the other side of the diaphragm, being under atmospheric pressure, means controlled by the diaphragm of the second penumatic for controlling an atmospheric vent opening in one of the chambers of the first pneumatic, whereby to actuate the diaphragm of the said first pneumatic for controlling the movement of the valve and means interposed in the line forward of the valve, actuated by an increased flow of air in the tube, resulting from the ej'ectment of the last carrier from said tube while the valve is open whereby said means controls the movement of the diaphragm of the second pneumatic, which in turn closes the atmospheric vent in the chamber of the first pneumatic, thereby causing the diaphragm of the latter to close the valve, said means including a spring for opposing the movement of the diaphragm in the direction for venting the chamber of the first pneumatic,

'2. In the combination set forth inclaim 1, said means comprising a battle, axially spaced relative to the diaphragm of the second pneumatic and movable relative thereto by an increased flow of air through the tube caused by the discharge of the last carrier in said tube. 4

3. In a pneumatic dispatch apparatus, including a transmission tube for a carrier with an air line connecting it to a source of suction; a normally closed valve interposed in the line between the tube and the source of suction, a reduced flow of air being permitted through the tube when the Valve is closed; a pneumatic for operating the valve said pneumatic comprising two chambers both exposed to suction when the valve is closed, one of said chambers being provided with a port for venting to atmospheric pressure, a second pneumatic provided with a diaphragm forming two chambers, one being constantly exposed to the pressure in the tube and the other to atmospheric pressure, a member supported in and extending concentrically through said diaphragm and beyond the chamber at atmospheric pressure, and provided at its end with a valve arranged for controlling the port in the chamber of the first pneumatic for regulating the valve movement under the control of said first pneumatic, a baflle plate disposed axially on said member in the path of travel of the air in the tube to the valve, said baflle being axially movable by an increased flow of air in the tube resulting from the dis charge of the last carrier therefrom, such closed, a pneumatic for operating the valve,

comprising two chambers each being exposed to suction whenthe valve is closed, one of the chambers having a port for venting it to atmospheric pressure; a second pneumatic having a diaphragm between two chambers, a portion of said pneumatic being operatively connected in the line forwardly of the valve and provided with a port constantly exposing one of the chambers to the pressure in the .line, the other chamber being subjected to atmospheric pressure, a member extending through the chambers and the diaphragm and movable therewith, one end of said member being adapted to control the atmospheric vent in the chamber of the first pneumatic, a bafile mounted on said member in spaced relation to the port, and dimensioned to overlap said port.

. 5. In the combination set forth in claim 4;, said bafile being movable laterally away from said port, together wit-h the diaphragm and member when the air flow in the line is materially increased, and a spring normally tending to assist said movement, thereby permitting said member to close the vent in the chamber of the first pneumatic for closing the valve.

6.-In a pneumatic dispatch apparatus including a transmission tube for a carrier, with an air line connecting it to a source of Suetion, a normally closed valve interposed in the line between the tube and the source of suction, a minimum flow of air being permitted through the line while the valve is closed, a 'ruieumatic for operating the valve, comprising two chambers each being exposed to suetion when the valve is closed, one of the chambers having a port for venting it to atmos-,

pheric pressure; a second pneumatic having a diaphragm between two chambers, a portion of said pneumatic being operatively connected in the line forwardly of the valve and provided with a port therein constantly exposing one of the chambers to the pressure in the line, the other chamber being subjected to atmospheric pressure, a member extending through the chambers and the diaphragm and movable therewith, one end of said member being adaptedto control the atmospheric vent in the chamber of the first pneumatic, a baflie dimensioned smaller than said port and normally interposed therein on said'member, and means on said member for limiting the movement of the battle in said port.

7 In a pneumatic dispatch apparatus including a transmission tube for a carrier, with an air line connecting it to a source of suction, a normally closed valve interposed in the line between the tube and the source of suction, a minimum flow of air being permitted through the line while the valve is closed, a

pneumatic for operating the'valve, comprising two chambers, each being exposed to suction when the valve is closed, one of the chambers having a port for venting it to atmospheric pressure; a second pneumatic having a diaphragm between two chambers, a portion of said pneumatic being operatively connected in the line forwardly of the valve and provided with a port therein constantly exposing one of the chambers to the pressure in the line, the other chamber being subjected to atmospheric pressure, a member extending through the chambers and the diaphragm and movable therewith, one end of said member being adapted to control the atmospheric vent in the chamber of the first pneumatic, the chambers of the'second pneumatic being connected by a by-vpass controlled bya valve, and

means on said member adapted to close the chamber of the second pneumatic which is exposed to the pressure in the line upon an increase in flow of air in the line resulting from the discharge of the last carrier from the tube. V, i

' 8. In the combination defined in claim 7, said means including a sleeve slidably mounted on said member, provided with a valve normally adapted to yieldingly open said chamber to the pressure in the line, and a baffle on the member co-operating with said port for controlling said valve.

SAMUEL OLSON. 

